Overview

Down syndrome is a chromosome disorder associated with intellectual disability, a characteristic facial appearance, and low muscle tone in infancy. The degree of intellectual disability varies from mild to moderate. People with Down syndrome may also be born with various health concerns such as heart defects or digestive abnormalities. They also have an increased risk to develop gastroesophageal reflux, celiac disease, hypothyroidism, hearing and vision problems, leukemia, and Alzheimer disease. Down syndrome is caused by having three copies of chromosome 21 (called trisomy 21) instead of the usual two copies and is typically not inherited.[1] Treatment focuses on the specific symptoms in each person.

The Genetic Alliance is an international coalition comprised of more than 600 advocacy, research and health care organizations representing millions of individuals with genetic conditions. Click on the link to view information on this topic.

In Depth Information

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Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.

PubMed is a searchable database of medical literature and lists journal articles that discuss Down syndrome. Click on the link to view a sample search on this topic.